Flaccus (flă´kəs), family of the ancient Roman gens of Fulvius. Marcus Fulvius Flaccus, a Roman consul in 264 BC, was the founder of the family. His son, Quintus Fulvius Flaccus, was Roman consul four times (237, 224, 212, 209 BC), censor (231), pontifex maximus [high priest] (216), and urban praetor (215). In the Second Punic War he defeated (211) the Carthaginians near Beneventum, captured (211) Capua, and overcame (209) Hannibal's garrisons in Lucania and Bruttium. Cnaeus Fulvius Flaccus, Quintus's brother, was convicted of cowardice against Hannibal in 210 and went into voluntary exile. Quintus Fulvius Flaccus, his son, waged war successfully against the Celtiberians (182–181) and the Ligurians (179). He eventually went mad and hanged himself. Marcus Fulvius Flaccus, grandnephew of the first Quintus, lived in the 2d cent. BC and was a supporter of the liberal measures of the Gracchi family. As consul in 125, he proposed to make all allies Roman citizens. This proposal, which met Senate opposition, led to the Social War. He was sent to subdue the Salluvii, who had attacked the Massilians, and returned to Rome in triumph. He was killed in 121 along with Caius Sempronius Gracchus and a number of his supporters.